Add the "virtual" keyword on method overrides that are missing it.

remoting/jingle_glue/xmpp_socket_adapter.h

 // Copyright (c) 2009 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef REMOTING_JINGLE_GLUE_XMPP_SOCKET_ADAPTER_H_
 #define REMOTING_JINGLE_GLUE_XMPP_SOCKET_ADAPTER_H_
 
 #include <string>
 
 #include "third_party/libjingle/source/talk/base/asyncsocket.h"
@@ skipping 21 matching lines @@
   virtual int GetError() { return wsa_error_; }
 
   void set_firewall(bool firewall) { firewall_ = firewall; }
 
   virtual bool Connect(const talk_base::SocketAddress& addr);
   virtual bool Read(char* data, size_t len, size_t* len_read);
   virtual bool Write(const char* data, size_t len);
   virtual bool Close();
 
 #if defined(FEATURE_ENABLE_SSL)
-  bool StartTls(const std::string& domainname);
+  virtual bool StartTls(const std::string& domainname);
   bool IsOpen() const { return state_ == STATE_OPEN
                             || state_ == STATE_TLS_OPEN; }
 #else
   bool IsOpen() const { return state_ == STATE_OPEN; }
 #endif
 
   sigslot::signal0<> SignalAuthenticationError;
 
  private:
   // Return false if the socket is closed.
@@ skipping 25 matching lines @@
   void FlushWriteQueue(Error* error, int* wsa_error);
 
   void SetError(Error error);
   void SetWSAError(int error);
   DISALLOW_COPY_AND_ASSIGN(XmppSocketAdapter);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_JINGLE_GLUE_XMPP_SOCKET_ADAPTER_H_